Method of forming an impregnated textile bobbin

ABSTRACT

A process for producing textile bobbins having improved performance characteristics and life properties which comprises impregnating a bobbin blank which is at least in part of greater than final dimensions with a selected impregnant that will cure into a hard non-softening wear-resistant surface, curing the impregnant to form the surface aforesaid and subjecting the cured surface to an abrading operation reducing the oversize part of the bobbin to final dimensions.

w United States atent 1 [111 3,729,813

Marston et ai. 51 May 1, 1973 [54] METHOD OF FORMING AN 2,424,861 7/1947 Snow ..l17/64 R UX 3,011,903 12/1961 Clocketal ..117/64RX IMPREGNATED TEXTILE BOBBIN 3,029,159 4/1962 Bliven et a1 ..1 17/59 [75] Inventors: James W. Marston; Percy J. Bolton,

both of Campton, NH. Primary ExaminerCharles W. Lanham Assistant Examiner-D. C. Reiley, I11 [73] Assignee. ltlorth American Rockwell Corpora- Anomey john R. Bronaugh et a].

hen, Pittsburgh, Pa.

[22] Filed: Jan. 24, 1972 [57] ABSTRACT [21] A 1 N 220,185 A process for producing textile bobbins having improved performance characteristics and life properties which comprises impregnating a bobbin blank which is [52] US. Cl ..29/527.2, 1 17/59, 1 17/64 R, at least in part of greater than final dimensions with a 242/ l 18, 2 selected impregnant that will cure into a hard non-sof- [51] Int. Cl. ..B23p 25/00 tening wear-resistant surface, curing the impregnant to [58] Field Of Search ..l17/59, 64 R; form the urface aforesaid and subjecting the cured 242/1 18, 125; 29/5271, 527.2; 51/327 surface to an abrading operation reducing the oversize part of the bobbin to final dimensions. [56] References Cited UNITED STATES PATENTS 7 Claims, 4 Drawing Figures 2,020,172 11/1935 Cotchett ..117/59 i 4 I Q k ic 1 METHOD OF FORMING AN IMPREGNATED TEXTILE BOBBIN BACKGROUND OF THE INVENTION Textile bobbins to which the present invention applies are frequently fabricated from various types and forms of woods and plastics, as well as other natural and synthetic substances. The bobbins comprise a butt portion and a barrel portion of lesser diameter than that of the butt portion. The barrel and butt portions may be formed integrally or they may be formed as separate units and then secured together subsequently. The barrel portion of the bobbin is the portion upon which yarn is stored and it is the portion that is subject to abrasion and compression by the yarn. The condition of the surface of the barrel affects the manner in which yarn feeds from the bobbin and when the surface is damaged by yarn abrasion or compression, this affect is adverse. For example, when a barrel surface becomes uneven or roughened from yarn abrasion, the yarn will tend to cling to the bobbin and greater tension is then needed to free the yarn. On the other hand, compression of a bobbin barrel by yarn can become great enough as to actually change the dimensions of the barrel and again cause the yarn to be fed out at a tension different from that theoretically desired. This latter problem is particularly severe with certain synthetic yarns that are more tightly wound on bobbins than are the natural fiber yarns.

In the past the problem of protecting the yarn contacting surfaces of bobbins has been partially solved by producing bobbins of final dimensions and then impregnating them with a substance designed to give a harder more wear-resistant surface than would be present on the bobbin as initially formed. Other attempts at solving the problem have taken the form of applying surface coatings, such as lacquer, paint, enamels, varnishes, etc., to the surface of the bobbin. All of these methods, while partially successful, have not completely solved the problem. For example, bobbins impregnated according to the prior art have been difficult to form accurately to preselected final dimensions because the act ofimpregnating the bobbins tends to alter the size and this size variation is not necessarily the same between individual bobbins.

It is a principal object of this invention to provide an improved process for producing textile bobbins having smoother surfaces of more accurate dimensions than have heretofore been possible. It is a further object of this invention to provide an improved process for producing textile bobbins in which the trueness of the barrel portion with respect to the longitudinal axis of the bobbin is improved.

Other objects and advantages of this invention will be in part obvious and in part explained by reference to the accompanying specification and drawings in which:

FIG. I is a side elevation of a textile bobbin blank that has been formed to a shape for use in the present process;

FIG. 2 is a side elevation similar to FIG. I but showing yarn engaging cleats mounted in the shoulder of the butt portion;

FIG. 3 is a side elevation of the bobbin showing a portion of an abrading wheel which forms the bobbin to final configuration and dimensions; and

FIG. 4 is a side elevation ofa final textile bobbin according to this invention.

Generally, the process of this invention comprises providing a bobbin blank in which at least a barrel portion is slightly larger than is desired as a final dimension. The remainder of the bobbin, i.e., the butt portion, can be at its final dimensions or it too can be left slightly larger than final size if this should be desired. After the blank has been formed, it is then impregnated with a suitable impregnant that will cause the barrel to have a hard non-softening wear-resistant surface. After 0 impregnation, the impregnant is cured under the conditions necessary for the particular material selected. With the bobbins thus in a condition where they are cured but are still at least partially of greater than final dimensions, it is necessary that they be subjected to a final shaping operation. This operation is performed by an abrading operation, such as grinding, so that the surface is kept smooth and of uniform quality throughout. A preferred method for performing the abrading operation is by use of a centerless grinder so that the barrel extends accurately along the longitudinal axis of the bobbin.

Referring now to the drawings and particularly to FIG. 1, there is shown a bobbin blank 10 which is made up of a butt portion 11 and a barrel portion 12. The barrel portion 12 is of a diameter that is greater than the final diameter is to be. The butt portion 11 may be of slightly larger than final size but this is a matter of selection to the manufacturer, since the tolerances and surface condition of this portion of the bobbin do not demand the same critical control as does the barrel.

Immediately adjacent the butt portion 11, there is shown a shoulder 13 which is finished t0 final dimensions when the bobbin blank is prepared. This shoulder is present for the purpose of receiving bobbin cleats, as shown in FIG. 2. Between shoulder 13 and the main body of barrel 12 is a small groove or depression 14 which is provided to insure that adequate space is left between the outer surface of the barrel and the cleats for a yarn end to be engaged by the cleats when yarn is being wound on the bobbin. Obviously in the event that a non-cleated bobbin is being manufactured, then there would be no need to provide the finished shoulder 13 nor the groove 14. Further, it may be possible, depending upon the type of cleating used, to eliminate the annular recess 14. The particular configuration or type of bobbin shown here is shown only for purposes of illustration and discussion since the invention is not to be limited to the particular type of bobbin shown and described.

After the bobbin blank has been provided as discussed in connection with FIG. 1, cleats such as those indicated by the numeral 15 can be applied by pressing them directly into the annular shoulder 13 in proper overlying relationship with respect to the external surface or barrel 12. In the event other types of staples are to be used, for example a ring bearing cleat which is pressed or otherwise secured to the base of the barrel portion adjacent the butt, they also can be applied at this time prior to impregnation. It will be noted that the present bobbin blank has been formed as an integral unit from a single piece of starting material. It should, however, be pointed out that butt portion 11 can be constructed separately from barrel 12 and then secured to the barrel by any suitable means. For example, a molded plastic butt portion could be premanufactured and then assembled on the end of the barrel 12 by a frictional force fit. The usual method by which bobbin blanks are produced is by turning down the starting blank with an appropriate cutting tool. For example, a lathe point or a cutting blade may be used for the fabrication depending upon the type of material being worked on. During turning operations it is not unusual, particularly with bobbins being made from wood, to form annular grooves or ridges because of the nature of the cutting operation. Additionally, tearing of the fiber can also occur and this results in gross defects being found in the surface of the bobbin. To some extent it is possible to correct the roughness resulting from the turning operation by subsequent dressing operations but this is time consuming, expensive, and only partially successful in producing a good high quality bobbin surface. The surface irregularities resulting from the turning operation have also been partially compensated for through the application of the various types of coating materials mentioned earlier. In this instance when wear of the coating material occurs, the surface defects which were covered by the coating become visible and the bobbin is no longer as effective in operation.

After the cleats have been applied (if cleats are to be used) then the bobbin blank is impregnated with an impregnant that will cure into a hard non-softening wearresistant surface. For example, impregnation may be effected using an epoxy resin, an acrylic resin or an unsaturated polyester. Examples of specific types of resins and the conditions that are necessary to cure these resins can be found in U. S. Pat., No. 3,029,159; No. 3,243,140; and No. 3,577,271. Since the conditions of bobbin impregnation and curing are set forth in these patents, they will not be discussed further in this specification.

In the event that it should be desired to apply cleating after impregnation of the bobbin blank, it would be possible to suitably suspend the blanks in such a way that only the barrel portions are emersed within the impregnant. This procedure is advisable since the bobbins become so hard after impregnation that it is extremely difficult to force cleats into the shoulder of the butt portion without incuring substantial manufacturing losses. Of course, where the cleating is mounted on the bobbin by means other than being forceably driven into it, impregnation of the entire bobbin can be effected without regard to the hardness of the bobbin blank. The important consideration is that the entire barrel portion of the bobbin be thorougly impregnated in its oversized condition so that it can be abraded to final and true size. Obviously since the butt portion has metal rings secured upon it and these rings bear the contact with the shuttle mounting springs, dimensional control and hardness of the butt portion are not necessarily important considerations.

FIG. 3 shows the bobbin as it is being brought into working relationship with respect to an abrading apparatus 16. in this case the apparatus 16 shown is part of a centerless grinder. Centerless grinding is to be greatly preferred as the means for abrading the surface of barrel 12 to final configuration since this method insures that the axis of the barrel portion coincides exactly with the longitudinal axis of the bobbin. By this method, there is no possibility that the barrel of the bobbin will ossessany deviation in a direction away from the b0 bm axis, hus insuring trueness of a yarn feed during shuttle operation. As the impregnated bobbin is being abraded, it will gradually come into contact with the surface 17 after annular grooves 21 have been formed in the barrel by means of the ring-like rib portions 22 found on the surface of the bobbin grinder. The surface 17 acts to abrade the surface of barrel l2 and to remove material in a uniform manner and in such a way that the entire external surface of the bobbin is of uniform quality. Since there is a line contact, as opposed to point contact between the element which is reducing the size of the barrel and the barrel, there is no possibility of turning defects occurring.

At the same time that the barrel portion is being abraded the butt portion of the bobbin is brought into contact with the ring-like protrusions 23 to form the annular grooves 24 that receive metal rings. These metal rings are used for holding the bobbin in the shuttle springs during weaving operations.

Although the present invention has been described in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.

We claim:

1. In a process of producing a textile bobbin having a barrel portion upon which a yarn package can be built the steps comprising:

a. impregnating a bobbin blank having a barrel portion diameter of greater than final dimensions with a selected impregnant that will cure into a hard non-softening wear resistant surface,

. curing the impregnant to form a surface on at least the barrel portion of the bobbin blank that has the properties set forth in (a) hereof, and

c. subjecting the cured surface to an abrading operation to reduce the oversize barrel portion of said bobbin blank to final size.

2. The process according to claim 1 wherein said bobbin blank includes integral butt and barrel portions in which the barrel portion is of a size greater than its final dimensions.

3. The process according to claim 2 wherein said impregnant comprises a resin material.

4. The process according to claim 3 wherein said resin material is selected from the groups consisting of epoxy, acrylic or an unsaturated polyester.

5. The process according to claim 4 which further includes applying yarn engaging cleats to the butt portion prior to impregnation.

6. The process according to claim 4 which includes impregnating only the barrel portion of said bobbin blank, curing the impregnant and abrading the barrel portion to its final dimensions.

7. The process according to claim 6 which further includes the step of applying yarn engaging cleats to said butt portion. 

2. The process according to claim 1 wherein said bobbin blank includes integral butt and barrel portions in which the barrel portion is of a size greater than its final dimensions.
 3. The process according to claim 2 wherein said impregnant comprises a resin material.
 4. The process according to claim 3 wherein said resin material is selected from the groups consisting of epoxy, acrylic or an unsaturated polyester.
 5. The process according to claim 4 which further includes applying yarn engaging cleats to the butt portion prior to impregnation.
 6. The process according to claim 4 which includes impregnating only the barrel portion of said bobbin blank, curing the impregnant and abrading the barrel portion to its final dimensions.
 7. The process according to claim 6 which further includes the step of applying yarn engaging cleats to said butt portion. 